Pump having a varying output

ABSTRACT

This invention relates to pumps having a varying output of the type comprising a plurality of parallel pistons housed in a common barrel, a means for rotating the said barrel about its axis and an angularly variable plate in relation with the said pistons for varying or adjusting their axial shifting.

United States Patent Peron 51 May 9, 1972 [541 PUMP HAVING A VARYING OUTPUT [72] Inventor: Robert J. GH. Peron, Sclaigneaux-Sclayn,

Belgium [73] Assignee: G. Dumont Et Freres Societe Anonyme,

Sclaigneaux-Sclayn, Belgium [22] Filed: Sept. 12, 1969 [21] Appl. No.: 857,379

[30] Foreign Application Priority Data Sept. 26, 1968 Belgium ..72l.41()

[52] US. Cl ..91/488, 91/505 [51] lnt.Cl .F01b 3/00 [58] Field of Search ..91/505, 504, 472, 473, 486-489, 91/506; 417/218, 222, 270

[56] References Cited UNITED STATES PATENTS 2,733,666 2/1956 Poulos ..91/487X 2,888,806 6/1959 Teumer ..4l7/222 X 3,266,434 8/1966 McAluay .141 7/222 3,426,686 2/1969 Anderson ...41 7/21 8 2,667,862 2/1954 Muller ..91/473 3,116,698 l/l964 Kramer... .....9l/504 3,295,457 l/1967 Oram ..91/488 3,375,756 4/1968 Bienaime ..91/506 FOREIGN PATENTS OR APPLICATIONS 426,316 4/1935 Great Britain ..41 7/269 645,947 7/1962 Canada 417/222 Primary E.\aminerWilliam L. Freeh A!mrney-Bacon & Thomas 5 7 ABSTRACT This invention relates to pumps having a varying output of the type comprising a plurality of parallel pistons housed in a common barrel, a means for rotating the said barrel about its axis and an angularly variable plate in relation with the said pistons for varying or adjusting their axial shifting.

2 Claims, 7 Drawing Figures PATENTEDMAY 9 1972 SHEET 1 BF 4 MES I N VE NTOR [Passer JG/l. Pzfialv BY arm/avers PUMP HAVING A VARYING OUTPUT This invention relates to pumps having a varying output of the type comprising a plurality of parallel pistons housed in a common barrel, a means for rotating the said barrel about its axis and an angularly variable plate in relation with the said pistons for varying or adjusting their axial shifting.

Numerous embodiments of pumps of that type are known, said pumps being however too intricate.

It is an object of the present invention to provide a simplified construction which is stronger and less expensive.

This simplification results both from a novel design in the arrangement of the constituting elements of the casing, the arrangement of the axially moving pistons and also the particular arrangement of the plate controlling and adjusting the axial movements of the pistons. Complementarily to these essential elements, the invention is also characterized by some characteristical dispositions which will be more clearly apparent from the following detailed description which has however no limitative character relating to the embodiment proper represented in the enclosed drawings.

FIG. 1 is a diametral longitudinal section through a pump having a varying output according to the invention, the pump being shown in its state of maximum output;

FIG. 2 is a longitudinal section on the line Il-II of FIG. 1;

FIGS. 3, 4 and 5 show respectively sections on the lines III- III, IVIV, VV ofFIG. 1;

FIG. 6 shows, on an enlarged scale, the portion indicated in F on FIG. 1;

FIG. 7 is a view similar to FIG. 6 of another embodiment of the indicated portion.

In this embodiment, the pump comprises the combination ofa casing 1, a rotating barrel equipment 2 and a mechanism 3 for varying or adjusting the output of the pump. The casing 1 comprises the assembly of two shells 4-5 and a back facing 6. The configuration of the shells 4-5 is such that they define laterally two co-axial bearings 7-8 having a packing 9-10 en gaged by diametrally opposite journals 11-12 forming part of the said mechanism 3 for respectively varying and adjusting the output of the pump. Between the two shells 4-5, is also provided a passage 13 for the member 14 actuating the device provided for varying and adjusting the output of the pump. The bottom of shell 4 has a central passage 15 both ends of which have a larger diameter. In the outer end 16, is housed a sealing packing 17 fastened by a resilient ring 18, while the inner end 19 forms the housing ofa roller or needle bearing 20 supported on the bottom 21 of the said widening through the intermediary ofa resilient washer 22 which is tensioned when mounting the pump, as described hereafter.

On the other hand, the shell 5 has the configuration of a duly profiled sleeve firmly interconnected with the said shell 4 through tightening screws 23. On the annular back face of shell 5 is firmly fastened the facing 6 through the intermediary of screws 24.

The inner wall of shell 5 has an annular shoulder 25 housing the crown 26 supporting the roller or needle bearing 27 which abuts on the outer face of the barrel 28. The said crown 26 is made stationary by a stop ring 29 housed in a peripheral corresponding groove of the inner face of shell 5. The barrel 28 is traversed axially by a passage consisting namely of three sections having different diameters 30, 31, 32 respectively. The axis 33 is interconnected with the said barrel 28 through the pin 34 and it is extended to rest upon shell 4 through the intermediary of the said bearing 20. This axis has a projecting section for fastening the driving device (not shown). On both sides of the bottom of the said shell 4, the axis 33 has stop rings 37-38 housed into the peripheral grooves -36. The axis 33 has still, in its rear portion, an axial channel 39 opening into a diametral channel 40 which opens in turn into the free space of the casing 1 defined by shells 4 and 5. The barrel 28 has a number of cylindrical housings 41 equally spaced and disposed at an equal distance form the longitudinal axis of the said barrel. The said housings or cylinders are each extended by a chamber 42 in relation with a secant passage 43 opening onto the rear face of the barrel. There are namely provided seven housings or cylinders 41 disposed on a crown. It could be also possible to provide pumps with a more or less important number of such housings, e. g. five or nine housings. Each housing engages with a slight fit a hollow piston 44 the projecting portion of which is terminated by a spherical head 45. In each hollow piston 44, is provided an axial rod 46 having a conical head 47 the top of which rests upon the center of the conical bottom 48 of the hollow space of the piston. In each of the latter, surrounding the rod 46, is disposed a return spring 49 leaning, on one hand, upon the said head of the axial rod 46 and, on the other hand, upon the bottom 50 of the corresponding chamber 42 of the barrel 28. The spherical head 45 of each piston is freely housed in a bearing 51 and these various bearings are supported on a ring 52 having a hub 53 defined interiorly by a cylindrical tapered wall 54-55. This ring 52-53-54 is housed in an oscillating plate 56 upon which it is supported through the intermediary of a ring 57 and bearings 58-59. The previously mentioned journals 11-12 form part of the said oscillating plate 56 and, by means of said journals, the said plate rests in the previously mentioned packings 9-10 through the intermediary of bushings 60-61. The said packings and bushings are kept into position by means of pairs of stop rings 62-63 and 64-65 respectively.

The back face of facing 6 has two threaded holes 66 and 67 for fastening a suction conduit and a discharge conduit respectively. Each hole 66-67 is extended by a port 68-69 respectively under the form of a ring portion extending each along an arc of about These annular ports 68-69 open onto the front face of facing 6 in front of the adjoining face of the barrel 28, i.e. also in front of the back face of the barrel traversed by the said secant passages 43.

The front face of facing 6 has still a central circular recess 70 coaxial with the central axial passage 30 of barrel 28.

In another embodiment of the head of the hollow pistons 44, as shown by the radial section of FIG. 7, this head may have an axial channel 71 opening into a free space 72 defined by the front butt face of the said hollow piston 44 and the corresponding portion of the spherical wall defining the recess of bearing 51.

On the other hand, the bottom of the said recess is traversed throughout by a hole 73 thereby opening onto the front face of the said ring 52. The shell 4 of the casing has a number of tapped holes 74 disposed in a crown about the longitudinal axis of the pump so that the driving motor thereof or any other suitable driving device may be fastened thereto.

The operation proper of this pump having a varying output is very simple since the continuous rotation of axis 33 imparts the same movement to the barrel 28 and the various hollow pistons 44 bearing thereon. The movement of the latter is conditioned by bearings 51 which are guided by ring 52. It results that the length of the linear movement of the hollow pistons 44 in the cylindrical housings 41 of the barrel 28 is directly function of the angle a of the said plate 52 relative to the longitudinal axis of the pump. To any variation in the one direction or the other of angle a will correspond an increased or decreased output of the pump.

In addition to the conventional lubricating action of the oil bath, this pump will take advantage of the internal and additional oil circulation via passages 30-39-40 of the axial portion of the pump and, on the other hand, in the particular case of FIG. 7, via the axial channel 71, the free space 72 and the hole 73 provided in the head of the hollow pistons 44 or the bearings 45.

The so conditioned pump has outstanding advantages on the technical, industrial and economical points of view. In fact, the fundamental design gives rise to a very easy manufacture owing to the particular morphology of the essential constituting elements of the pump: the casing l, the rotating barrel equipment 2 and the mechanism for varying the output of the pump.

In addition to the very simple structure of the various constituting parts together with the extreme compactness and sturdiness of these parts, the pump is very easily mounted and dismantled for possible repair and maintenance purposes.

The number of parts provided for making a pump having a varying output is also relatively very reduced, thereby giving rise to a very competitive cost price with the very nature of the constituting parts.

Owing to the design and the morphology of the barrel with its hollow pistons and the channels connected alternately with the inlet conduits and the outlet conduits of the pump, an optimum operation is obtained. in addition, the parts having a relative movement are permanently lubricated by equilibrating the oil pressures, thereby contributing efficiently to the durability of the pump.

The device for varying the output of the pump is actuated via any suitable member namely shown diagrammatically by lever 14 under such conditions that, by means of a minimum effort and without producing interfering stresses between the rotating barrel device and the adjustment plate 3, it may oscillate about the virtual center with the minimum actuating effort.

The axial and tangential stresses upon the oscillating plate 56 through the intermediary of bearings 58-59 occur with an extreme flexibility, which is particularly favorable to the good preservation of the internal elements of the pumps.

It is of course apparent that the so conditioned pump may be provided for any output.

What I claim is:

1. in a variable output displacement pump: a casing; a barrel rotatably mounted within said casing, and having a plurality of cylinders therein arranged generally parallel to the axis of rotation of said barrel; means for rotating said barrel; a piston reciprocally received within each of said cylinders, said pistons each having a bore therein extending inwardly from the rear end thereof and terminating in a conical bottom wall; a swash plate received within and journaled to said casing, said swash plate confronting the front ends of said pistons and being tiltable relative to the front face of said barrel; an axial rod received within the bore of each piston, and having a conical head seatable on said conical bore bottom wall; a return spring associated with each axial rod for urging the conical head thereof into engagement with its associated conical bore bottom wall; a generally spherical head on the front end of each of said pistons; each of said pistons including a lubrication channel leading from the conical bottom of said piston bore to the surface of said spherical head; bearing means carried by said swash plate, said spherical heads being freely received by said bearing means; and an activating member connected with said swash plate and operable for tilting the same.

2. in a pump as recited in claim 1, wherein said casing comprises a pair of shells secured together in confronting relationship, said shells having a passage formed at the juncture thereof and through which said activating member extends. 

1. In a variable output displacement pump: a casing; a barrel rotatably mounted within said casing, and having a plurality of cylinders therein arranged generally parallel to the axis of rotation of said barrel; means for rotating said barrel; a piston reciprocally received within each of said cylinders, said pistons each having a bore therein extending inwardly from the rear end thereof and terminating in a conical bottom wall; a swash plate received within and journaled to said casing, said swash plate confronting the front ends of said pistons and being tiltable relative to the front face of said barrel; an axial rod received within the bore of each piston, and having a conical head seatable on said conical bore bottom wall; a return spring associated with each axial rod for urging the conical head thereof into engagement with its associated conical bore bottom wall; a generally spherical head on the front end of each of said pIstons; each of said pistons including a lubrication channel leading from the conical bottom of said piston bore to the surface of said spherical head; bearing means carried by said swash plate, said spherical heads being freely received by said bearing means; and an activating member connected with said swash plate and operable for tilting the same.
 2. In a pump as recited in claim 1, wherein said casing comprises a pair of shells secured together in confronting relationship, said shells having a passage formed at the juncture thereof and through which said activating member extends. 